5-HT-related drugs and human experimental anxiety.
Clinical observations and double-blind studies demonstrated an anxiolytic effect of drugs that facilitate serotonergic transmission on several anxiety disorders. There is a latency of several weeks for their anxiolytic effect to take place. There may be, in addition, a biphasic effect, i.e., an acute anxiogenic effect followed by an anxiolytic effect after chronic use. In addition, acute administration of m-chlorophenylpiperazine (MCPP), an agonist of 5-HT-1 receptors, increased anxiety in normal volunteers as well as in patients with panic or obsessive-compulsive disorders. Studies in health volunteers have been performed in our laboratory to explore the acute effect on human anxiety of drugs that selectively influence 5-HT neurotransmission. We observed that acute administration of chlorimipramine enhanced the rise in anxiety induced in healthy volunteers by speaking in front of a video camera. With a similar experimental design, we also demonstrated an anxiogenic effect of metergoline, a nonselective 5-HT receptor blocker. It is suggested that the proanxiogenic effect of acute administration of 5-HT uptake inhibitors may be due to impaired 5-HT neurotransmission.
Zuardi
A W
AW
Department of Neuropsychiatry and Medical Psychology, FMRP University of São Paulo, Ribeirão Preto, Brazil.
D001007:Anxiety / Q000503:physiopathology*; D006801:Humans; D012701:Serotonin / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology
D012702:Serotonin Antagonists; D012701:Serotonin